1. Technical Field
The present disclosure relates to steam heated cooking devices, and more particularly, to a user adjustable apparatus for altering cooking speed, water usage and energy efficiency in a steam heated cooking device.
2. Description of Related Art
Steam cookers are widely used in commercial food service applications because they can rapidly re-warm or cook large quantities of food while maintaining excellent food quality. In order to heat and/or cook food in a steam cooker, water is heated until it changes phase to become steam. The steam is then circulated through the cooker using a fan or other circulation mechanism to allow the steam to contact the food and increase the temperature of the food.
Air acts as an insulator around food in steam cookers, slowing the cooking process. To alleviate this problem, air may be purged from the cooker either through an open vent to atmosphere, a drain, a condenser or a vacuum pump.
Some steam cookers, including many for use in commercial applications, supply a large volume of steam to the cooker continuously. Any steam not condensed by the food is vented from the steamer. In many cases, the vented steam quantity is sufficiently large to warrant the use of a cold water condenser, which condenses excess vented steam back into liquid water before routing it to a drain. While these high-volume steamers can cook food quickly, they are also very energy inefficient because substantial heat energy in the vented and condensed steam is lost to the surrounding environment.
In addition to energy consumption, large volumes of water are also used in the condenser. In some cases, this condenser wastewater may be up to 60 gallons per minute, leading to substantial operational expense. Further, steamers which use such large volumes of water must be connected to a potable water supply and plumbed into a drain, further exacerbating the expense and complexity of their use.
Thus, managing water and energy usage has been the subject of substantial design efforts. Some known steam cookers use pressure or temperature measurement to control the amount of steam supplied to the food chamber or generated in the cooker. These cookers achieve higher levels of energy efficiency, use less water and may not require the use of water and drain lines.
For example, one known steam cooker utilizes a steam-cooking apparatus with a control system which operates to maintain a constant pressure and/or water temperature within the cooker. This is the Steam ‘N’ Hold steam cooker, available from AccuTemp Products, Inc. of Fort Wayne, Ind., and described in a publication entitled “AccuTemp Steam ‘N’ Hold Service Manual, Serial Numbers 25384 and Up,” a copy of which is submitted on even date herewith in an information disclosure statement, the entire disclosure of which is hereby expressly incorporated herein by reference. The Steam ‘N’ Hold steam cooker reduces the internal atmospheric pressure of the cooking chamber, thereby lowering the temperature at which water begins to boil. This allows the operator to control the temperature of the steam for cooking Controlling the steam temperature gives the operator the ability to cook the food to the desired temperature without over-cooking. Once the cooking time expires, the Steam ‘N’ Hold steam cooker automatically enters a “Hold” mode in which a thermostat regulates the internal temperature of the cooking chamber and the vacuum is released to return the cooking chamber to normal atmospheric pressure. In this “Hold” mode, steam is no longer generated and the cooking chamber is held at the desired temperature at a relative humidity of 100%.
While the AccuTemp Steam ‘N’ Hold steam cooker does reduce operational costs related to energy and water consumption, cookers using lower steam throughputs cook more slowly than cookers that vent large amounts of steam.
Another known device is the Smart Kitchen Multicooker shown and described in the brochure entitled “Smart Kitchen Multicooker, George Foreman Healthy Cooking” a copy of which is submitted on even date herewith in an information disclosure statement. The Smart Kitchen Multicooker utilizes a constant power input, which ultimately determines the amount of steam produced. That is to say, once the cooker is at temperature (i.e., the water in the cooker is boiling), essentially all the power input to the device is used to generate steam. A variable vent is provided to prevent the lid of the device from lifting, which would allow steam to escape. The size of the vent may be adjusted to whatever size is necessary to keep the lid engaged with the steam vessel. Vent adjustment in the Smart Kitchen Multicooker does not affect steam generation, energy usage or cooking speed. Rather, these quantities are determined solely by the temperature control setting; once the cooker is warmed up to a stable cooking temperature, the amount of power input is directly correlated to the temperature control setting and is unaffected by the size of the vent.
An improvement over the foregoing is desirable.